Search

Rising demand for solar power generation will lead to increased land use competition, and thus to potential economic and social conflict. A solution to this challenge is to produce food and energy within an agrophotovoltaics (APV) system. Since 2017, governments in Japan, France, Massachusetts (USA), South Korea, and China have introduced policies supporting APV implementation. Governments considering APV implementation – e.g. in India and Germany – for evidence-based policy making are demanding information on how levelized cost of electricity (LCOE) of APV differs from that of conventional ground-mounted photovoltaics (PV), as well as on how additional costs associated with APV installation relate to the benefit of maintaining agricultural activity under APV. Data for a techno-economic price-performance ratio calculation has been retrieved from an inter- and transdisciplinary APV case study in Germany. We observed that the LCOE of APV with €0.0828 kWh−1 is 38% higher than that of ground-mounted PV, resulting in an annual cropland preservation price of €9,052 ha−1 a−1. The annual revenue of potato and winter wheat production under APV resulted in a performance of €10,707 ha−1 a−1 and €1,959 ha−1 a−1 respectively, leading to a beneficial price-performance ratio of 0.85 for potato production and, with a ratio of 4.62, a disadvantageous result for winter wheat. Overall, APV is not necessarily recommended in crop rotating systems. However, in combination with permanent cultures – e.g. berries, fruits, or wine grapes – as the price for these types of applications is lower, while at the same time providing higher performance by optimizing techno-ecological synergies.

For over two decades, latent heat storage (PCM) systems in building applications have been regarded as a promising technology for preventing overheating in the warm season without increasing cooling energy demand. This study aimed to investigate whether PCM can have a noticeable influence on thermal comfort even after up to 14 years of operation, which has not yet been investigated. For this, we collected PCM material samples in some buildings, which we then examined in the DSC laboratory, and analysed a real building application in southern Germany in detail by collecting measurement data and creating building simulations. The DSC measurements revealed a decrease in performance by 12–26%. However, the simulation results did not show a clear decrease in the performance of the PCM. Instead, they indicated that the paraffin-based PCM still had a positive effect on thermal comfort, reducing room temperatures by a maximum of 1.06 K and in average by 0.34 K during working hours. The PCM also reduced cooling degree hours by 15% during the hot months of July and August. An analysis of the user behaviour showed that there might be potential for improving thermal performance, especially through better use of blinds, windows and night ventilation.

Combining agriculture and photovoltaics on the same land area gains in attention and political support in a growing number of countries accompanied by notable research activities in France, USA and Korea, amongst others. This study assesses the technical feasibility of agrivoltaic (APV), while it gives insights on how to design an APV system. Furthermore, it analyses the electrical yield and the behavior and productivity of four crops grown in Germany's largest agrivoltaic research facility installed in 2016 near Lake Constance within the research project APV-RESOLA by Fraunhofer Institute for Solar Energy Systems ISE. The German design differs from most other agrivoltaic approaches by allowing for a wide range of machine employment, facilitated by a vertical clearance of 5 m and a width clearance of up to 19 m. Crops cultivated under the APV system and on the reference field under a crop rotation scheme include potato, celeriac, clover grass and winter wheat. The land use efficiency measured by the Land Equivalent Ratio (LER) indicated a rise between 56% and 70% in 2017 while the dry and hot summer in 2018 demonstrated that the agrivoltaic system could increase land productivity by nearly 90%. Radiation simulations showed that deviating from full south by around 30° resulted in equal distribution of radiation on ground level, representing the basis for the agrivoltaic design. Considering climate change and increasing land scarcity, our overall results suggest a high potential of agrivoltaics as a viable and efficient technology to address major challenges of the 21rst century.